Shotgun choke and compensator



March 11, 1952 l. D. VlRONDA SHOTGUN CHOKE AND COMPENSA'I'OR Filed June 25, 1949 ZSnventor ITALO D. I/IRON DA (Ittomeg Patented Mar. 11, 1952 iJNi'i'ED STATES PATENT orrics This invention relates in general to a gun com- Persons acquainted with the use and opera tion of shot guns, especially on trap or skeet ranges, have long recognized the need for a shot gun compensator which would eliminate the loud report created when the, impelling gases behind the gun charge expand as they pass from the discharge end of the gun barrel.

Persons acquainted with the ballistics of a shot gun have also recognized that the expansion of the impelling gases tends to spreadflthe pattern of the shot, evenwhen a choke is used, if no provision is made for dissipating the expansive potential of the impelling gases beforethey. reach the discharge end of the gun barrel;

Numerous shot gun compensator's, such as the one disclosed in Patent No. 2,453,747, have been developed to prevent distortion of the gun shot pattern by the expending impelling gases byproviding one or more openings in the sidewall of the compensator through which the gases may escape progressively. However, neither this type of compensator nor other presently known compensators eliminate the loud report causedby the expanding gases. In fact, the report is actually more objectionable, especially to persons standing near the gun, where a compensator having said sidewallopenings is used.

Patent No. 2,165,457 discloses another type compensator, which is designed for use with a gun firing a single projectile. The numerous openings between the inner chamber and the annular chamber in this compensator permit too rapid an escape of the impelling gases and a corresponding premature dissipation of the impelling force. Likewise, this compensator does not eliminate the objectionable noise.

Accordingly, a primary object of my invention is the provision of a compensating device cooperable with the muzzle of a shot gun barrel whereby the damaging effects upon the shot pattern, due to the expansion of the impellinggases, is positively prevented and, further, whereby the objectionably loud report incident to the expansion of such-impelling gases is satisfactorily mufiied.

A further object of this invention is the provision of a shot gun compensator, as aforesaid, for use in combination with gun chokes of varying internal diameters, said chokes becoming an integral part of my invention.

A further object of this invention is the pro- 2 claims. (Cl. 42-79) vision of a shot gun compensator, as aforesaid, whichis simple in structure and easily adaptable to the muzzle of a shot gun under a variety of conditions.

Other objects and purposes of this invention will become apparent topersons familiar with this type of equipment upon referring to the accompanying drawings and upon reading the following specification;

In. meeting those objects and purposes heretofore mentioned, as well as others incidental thereto and associated therewith, I have provided a compensator. cooperable with the muzzle of a shot gun barrel providing an inner cylindricalchamber coaxial with an-having an internal diameter substantially equal to the internal bore of the shot gun barrel. An enclosed annular chamber is provided around and walled from the inner chamber by means of an outer tube supportable upon the gun barrel near the-muzzle thereof. An entrance-passageway is provided between the inner chamber and the annular chamber at one end of theannular chamber. An exit passageway is provided between the' annular chamber and the inner chamber at the opposite end of the annular chamber. The inner and annular chambers arecompletely walled on from each other between the entrance andexi-tpassageways. A choke of a conventional type is mounted upon the extended end of the outer tube. Thus, a portion of the impelling gases behind the gun charge may escape into the annular chamber through the entrance passageway and return to the inner chamber through the exit passageway ahead ofthe gun charge. The expansion ofthesegases as they pass into the annular chamber through the entrance passagewayfurther dissipates the explosive potential thereof. Thus, the noise disturbance created by these preceding cases, when they pass through thte discharge end of the gun ahead ofthe gun charge, is much'less thant-he' disturbance caused by present guns. The impel-ling gases, remaining behind thegun charge, will be sufiiciently reduced in explosive potential both by expansion and reduction in volume as to create a much less intense report, when they discharge from the of a shot gun, especially when one of the presa ently known compensators is used; v

For illustrations of preferred embodiments of I my invention reference is made to theaccome,

' panying drawings in which:

Figure l is a centrally cross-sectioned'view of The internal diameter of the inner tube 11' is preferably slightly larger, such as .030 of an inch, than the barrel bore I6 at the gun muzzle be slightlyexpandingly tapered toward the gun muzzle I3. There will be a slight tendency for Figure 4 is a sectional'view substantially as taken along the line IV-aIV of Figure 1.

Figure 5 is a sectional View substantially takenalong the line V-V of Figure 2. V 7

Figure 6 is a sectional viewsubstantially as I taken along the line VIVI of Figure 1.

p c nstruction As shown in Figure 1 the'shotgun compensator I0 is comprised of a cylindrical mounting collar II which'issleeved upon and secured, asv

' by brazing, to a shot gun barrel I2 adjacent to the muzzle-13 thereof; Themounting'collar I I I is providedwith an integral, radially extending,'

annular flange I4'adjacent to the outer end thereof, which end is remotev from the gun muzzle externally I3; The mounting collar H is threaded between'the annular flange I4 and the the gun shot to disperse between the gun muzzle I3 and the inner tube I 7. Therefore, this taper, I in combination with the enlarged bore of the inner tube I1, prevents interference of the inner tube'end24 with the gun charge I9 as it passes through the space between the gun muzzle I3 and the end 24 of the inner tube I1.

The inner tube I! is preferably, but not necessarily, provided with an external, radially extending,'annularstop'fiange 34 .adjacent'to the end 24 thereof which bears against the support inner end thereof whichis adjacent to the gun I muzzle l3.

, For the purpose of convenience in description, the terms inner or inwardlyand' outer? or I outwardly as used in thisspecification shallbe understood to have reference to the geometric center of thecompensator I0 and will be applied either, in, a radial or axial direction as best serves the disclosure.

One end 20 of the outer'cylindrical solid tube I5, which tube is internally threaded near both ends thereof, is threadedly mounted upon the threaded portion of the mounting collar II and bears snugly against the annular flange I4; The outer tube, which is coaxial with the internal bore I6 of the gun barrel I2, extends substantially beyond the gun muzzle I3.

The outer tube I5 is positively secured upon the collar I I by means of a lock pin 33 (Figure 6) which is driven into an appropriate opening intersecting the external threads of the mounting collar I l and cooperating threads of the outer tube I5 and preferably perpendicular to the axis of the gun barrel I2.

An inner, cylindrical solid tube Il (Figures 1 and 4), which is coaxially disposed within the outer tube I5 is spaced therefrom and supported thereon by a pair of spaced, support rings 2I and 22 to provide an annular chamber I8 between the inner and outer tubes I1 and I5, respectively. The support rings 2I and 22 (Figure 4), which are preferably, but not necessarily, integral with the outer tube I5, are relieved by a plurality of axially disposed slots 23. Although the slots are shown in Figure 4 as substantially semi-circular and positioned along the inner wall of the rings, they may be of any size and contour desirable, such as substantially rectangular (Figure 5), and may pass through the rings between the said inner wall thereof and the outer tube I 5.

One end ,24 of the inner tube I! is spaced axially from the gun muzzle I3 thereby providing an entrance passageway 25 between the gun muzzle I3 and the end 24 of the inner tube I'I, communicating with the annular chamber I8.

3!] and the inner tube I1 communicating with v a ring 2!. The stop flange 34 prevents movement of the inner tube I! away from the gun muza zle I3.

The opposite end 21 of the'inner tube I1, remote from the gun muzzleIB, is spaced inwardly with respect to the extended end 28 of the outer tube l5; A shot'gun'chokeflhwhich may be of 'any; convenient conventional type having ex ternal threads at one end thereof, is threadedly 1 I 1 engaged by 'the'internal threads within the extended end 28 of the outer tube I5. The choke 39, when in operable position, is spaced from the I I 7 adjacent end'2'I of theinner tube I1 thereby pro- I viding an exit passageway 3I between the choke the annular'chamber I8.

An inner chamber 26, which extends from' within the gun muzzle I3 to the'd'ischarge end 1 I 32 of the gun choke 30, is defined by theinternal I bore of the gun muzzle I3, the inner tube I! and I the gun choke 30.

' Accordingly, it will be seen. thatthe gun choke 30, or a similar gun choke, constitutes a necessary and integral part of this invention.

The entrance passageway 25 connects the inner chamber 26 with the annular chamber I8 at the end thereof adjacent to the gun muzzle l3, and the exit passageway 3| connects the inner chamber with the annular chamber at the opposite end thereof.

Alternate structures An alternate shot gun compensator 40 (Figures 2 and 5) is comprised of a mounting collar M, which may be substantially identical to the above described mounting collar II, including an annular flange 42 extending radially and externally therefrom adjacent to the outer end thereof. However, in the alternate compensator 36, the mounting collar 4| is secured to the gun barrel, as by brazing, at a point spaced approximately two inches from the muzzle of the gun barrel. A plurality of entrance passageways 43, here six, are provided through the sidewall of the gun barrel I2a between the mounting collar 4I and the gun muzzle I3a, preferably adjacent to the mounting collar 4 I.

The mounting collar 4| is externally threaded, in a manner similar to that described with respect to the mounting collar II, for threaded engagement by cooperating internal threads at one end of a cylindrical outer tube 44, which outer tube may be similar in all respects to the cylindrical outer tube I5. The outer tube 44, which is coaxial with and extends beyond that portion of the gun barrel I2a between the mounting collar 4i and the gun muzzle I3a,"is spaced there- Furthermore, a portion of the internal bore of the inner'tube I'I at theend 24 thereof may The gun choke 36a is spaced from the gun muzzle |3a to provide an exit passageway 41 communicating with the annular chamber 46; An inner chamber 48 is substantially defined by that portion of the internal bore 16a of the gun barrel [2a between the mounting collar 4| and thegun muzzle I301, and the internal bore of the gun choke 3611.

Accordingly, the entrance passageways 43 connect the inner chamber 48 with the annular chamber as at the end thereof adjacent to the gun muzzle [3a. The exit passageway 41- connects the inner chamber with the annular chamber at the opposite end thereof.

The internal bore 16a of the gun barrel l2a may be counterbored from the gun muzzle |3a to a point on the opposite side of the entrance passageways 43, as shown in Figure 2, to prevent interference of the exit passageways 43 with the flight of the gun shot in the gun charge. A lock pin 33a, similar in all respects to the lock pin 33, may be provided for securing the outer tube 44 upon the mounting collar 4|, as above described.

Another alternate compensator (Figure 3) is comprised of a solid cylindrical inner tube 56 having a portion 51 of enlarged diameter which is sleeved upon and secured to the gun barrel [2b, as by brazing, at the muzzle I3b thereof. The remainder 58 of the inner tube 56, which preferably has an internal diameter slightly larger than the internal bore [6b of the gun barrel l2b, is coaxial with and extends away from the gun muzzle 13b. The enlarged portion 51 of the inner tube 56 is provided with an integral, external, annular flange 59, remote from the. small portion 58, and the remainder of the enlarged portion 51 is externally threaded. An outer, solid cylindrical tube 6| is internally threaded at one end 62 for threaded engagement with the threads on the enlarged portion 510i the inner tube 56. The outer tube 6|, which is coaxial with and extends substantially beyond the extended end of the inner tube 56, is spaced from and supported upon the inner tube small portion 58 by means of a support ring thereby providing an annular chamber 63 between the outer tube 6-! and the small portion 58 of the inner tube 56. The support ring 65 may be similar to the support rings 2| and 22 (Figures 4 and 5), hereinabove described in detail. A plurality of passageways 64 communicating with the annular chamber 63 are provided through the sidewall of the small portion 58 of the inner tube 56 adjacent to the gun muzzle 13b.

The outer tube 6] is provided with an internal gun choke 66 at the extended end thereof, having an internal bore 61. A space is provided between the extended end of the small portion 58 of the inner tube 56 and the adjacent portion of the choke internal bore 61 thereby creating an exit passageway 68 communicating with the annular chamber 63. An inner chamber 69 is substantially defined by the internal bore of the gun muzzle 1322, the small portion 58 of the inner tube 56 and the choke internal bore 61. A

q' sir 6 1ock-pin"33b (Figure 3), which may be substantially identical to the-lockpin 33, may be provided for locking the end 62 of the outer tube 6! upon the enlarged portion 51 of the inner tube 56;

Accordingly, the-entrance passageways 64 conmeet the inner chamber 69 with the annular chamber 63 at the end thereof adjacent to the gun muzzle 13b. The exit passageway 68 connects the inner chamber with the annular chamber-'atthe oppositeend thereof.

Operation The compensator l0 (Figure 1)and the alternate compensators and 55 (Figures 2 and 3), are: all. designedwith the following basic essentials in common: Aninner tube, a coaxial outer tube: spaced from the inner tube to provide an annular. chamber therebetween, an entrance passagewayfrom the inner chamber into the annular chamber at one end thereof, an exit passagewayfrom the annular chamber, at the other end. thereof, into the inner chamber and a gun choke,, either integral or otherwise, which becomes a cooperating part of the compensator.

Accordingly, a detailed description of the operation of the compensator [0 (Figure 1), given hereinafter, shall beunderstood as applicable in substance to the operationof the alternate compensators 40 and'.

- When. the gun charge 19, here shot and the wadding associated therewith, are passing through the inner tube I! a portion of the impelling gases are permitted to expand through the entrance passageways 25 into the annular chamber I8, then bypass the gun charge [9 through. the annular chamber l8 and return to the inner chamber 26i-through the entrance passageway. 25 ahead. of the gun charge [9, and finally precede the gun charge through the discharge-end 32 of 'thezgun choke 30. The expansion dissipates. a substantial amount of the expansive potential in .the said portion of impelling gases'which bypass the gun charge while it is in the inner tube. I1, thereby greatly reducing the explosion. created by these preceding gases as they are emitted from the discharge end 32 of the gun choke" 30.

Sincethe' impelling gases are much lighter and have much less inertia than the shot, a substantial portion will bypass the gun charge 19 through the annular chamber l8 while the gun charge I9 is passing through the inner tube I1. The: remaining impelling gases behind the gun charge, having been substantially reduced in volume by'the escape of 'a substantial portion thereof, produce only a minor explosion when they are emitted from the discharge end 32 of the gun choke 30 behind the gun charge I9. While the gun charge [9 is entering into and passing through the choke 30, thereby blocking the escape of the portion of impelling gases remaining behind the gun charge, said remaining gases are permitted to expand through the entrance and exit passageways 25 and 3|, respectively, into the annular chamber l6 thereby dissipating some of the explosive force remaining therein.

Accordingly, it may be seen that my compensator first divides the impelling gases which produce the objectionable report normally produced by present compensators, into two portions, one portion of which precedes the gun charge and one portion of which follows the gun charge from the discharge end 32 of the gun choke 30. The explosive potential of each of these two portions is further reduced by the expansion of the gases through the entrance and exit passageways into the annular chamber I8, surrounding the inner chamber 26 through which the gun charge 19 passes. Thus, the report produced by a shot gun equipped with my compensator is negligible by comparison with the explosive report produced by shot gun compensators of' the type presently in use.

Another advantage of my compensator resides in the fact that only a portion of the impelling gases are removed from behind the gun charge before the charge leaves the discharge end. 32 of the choke 30.

In addition to the above advantages of my compensator, it will be observed that the inner tube 11 in cooperation with the gun choke 30 tends to control the pattern of the shot through the entire length of the compensator thereby preventing losses in muzzle velocity due to an abrupt change in direction of any of the shot when they funnel through the gun choke. An excessive amount of funneling action upon the gun, charge materially reduces the muzzle velocity of the gun charge.

Although the above mentioned drawings and description apply to one particular, preferred embodiment of the invention, it is not my intention, implied or otherwise, to eliminate other variations or modifications which do not depart from the scope of the invention unless specifically stated to the contrary in the hereinafter appended claims.

I claim:

1. A muzzle device-for firearms of the shotgun type discharging a scatter shot charge, comprising the combination: externally threaded base means mountable on a shotgun muzzle; a cylindrical, unbroken, outer tubular member internally threaded at its one end for engagement with said base means, said outer tubular member having an internal diameter materially larger than the barrel of said gun; a choke member at the other end of said outer tubular member and co-axial therewith, having at its end closest to said base member an internal opening of a size approximating the internal diameter of said outer tubular member and thence tapering to a smaller internal diameter in a direction away from the muzzle of said gun; an inner, cylindrical, unbroken, tube arranged coaxially with respect to said outer tubular member and having its external walls parallel with the internal walls of said outer tubular member, said inner tubular member being axially spaced from the muzzle of said shotgun and being also axially spaced from said choke member; said inner and outer tubular members together forming an annular chamber of substantially constant cross sectional area from one end of said inner tubular member to the other end thereof; and means mounted internally of said outer tubular member for supporting said inner tubular member with respect to said outer tubular member, said means being perforated sufiiciently as not to restrict materially the passage of gases through said annular chamber.

2. A muzzle device for firearms of the shotgun type discharging a scatter shot charge, comprising the combination: base means mountable on a shotgun muzzle; a cylindrical, unbroken, outer tubular member having means at its one end for engagement with said base means, said outer tubular member having an internal diameter materially larger than the barrel of said gun; a choke member at the other end of said outer tubular member and co-axial therewith, having at its ends closest to said base member an internal opening of a size approximating the internal diameter of said outer tubular member and thence tapering to a smaller internal diameter in a direction away from the muzzle of said gun; an inner, cylindrical, unbroken, tube arranged co-axially with respect to said outer tubular member and having its external walls parallel with the internal walls of said outer tubular member, said inner tubular member being axially spaced from the muzzle of said shotgun and being also axially spaced from said choke member; and means supporting said inner tubular. member with respect to said outer tubular member, said means being perforated sufficiently as not to restrict materially the passage of gases through said annular chamber.

ITALO D. VIRONDA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

